View Full Version : Can you keep freshwater fish in Brackish tank??
Mrsoftey2
12-17-2003, 5:20 PM
is it possible to keep fresh water fish in brackish water? also can u keep mollies in freshwater??
OrionGirl
12-17-2003, 5:25 PM
Depends. There are some freshwater fish that can tolerate mild brackish conditions. Mollies can actually go the full range of marine to fresh, but prefer slightly harder water.
Do you have specific fish in mind?
Mrsoftey2
12-17-2003, 5:30 PM
right now I have a freshwater tank with 3fish 2 zebra danios and 1 albanio cory the tank has been cycled for quite a while
OrionGirl
12-17-2003, 5:33 PM
Cories won't go to brackish. They can tolerate medicinal levels nicely, but not brackish.
I have to say, keeping fish in water that is seriously different than their native water is pretty well asking for trouble. It tends to stress the fish, increasing their susceptibility to diseases and parasites. They also are not as colorful and active when stressed.
Mrsoftey2
12-17-2003, 5:39 PM
how should i change to brackish?? and do zebras do alright in Slightly Alkaline??
OrionGirl
12-17-2003, 5:47 PM
I've never kept danios in brackish conditions, so have no idea.
Converting is just a matter of using brackish water for water changes. Start with a low level of salt, less than 1.005, and gradually increase the amount of salt with each water change.
You will have to find a new home for the cory, and I would remove the danios as well. Just not a good idea to stress fish.
Mrsoftey2
12-17-2003, 5:48 PM
will it be harder to keep a brackish aquarium???
OrionGirl
12-17-2003, 5:58 PM
Maintaining the tank will be a bit more work. You have to test for salinity, and preparing the water for changes is an additional step. Cleaning is pretty similar to FW--though you have to deal with salt creep. FW topoffs for evaporation are critical in BW, since the evaporation increases salinity, and can cause problems.
Otherwise, it's not that different to maintain. You will be limited in what plants can go in, as well as fish. There are many, many fish sold as brackish that need full marine conditions as adults--and compared to either FW or SW, there are not that many BW fish in the trade.
Mrsoftey2
12-17-2003, 6:01 PM
Will brackish fish like guppies, swordtails,mollies, and drawf livebares still be able to live well in fw
Don't know about dwarf livebeaers but all the others do fine in freshwater and are most likely kept in freshwater at your fish store. If you really want a brackish tank I would suggest either getting a new tank or else give up your other freshwater fish. It will just be easier that way.
Also don't get salt for freshwater aquariums. It is just NaCl. You really need to buy marine salt.
Mrsoftey2
12-17-2003, 6:17 PM
Can u suggest any furnishings for my tank if i do keep the fish i suggested ??
i also don't know if i should get an airator or not
What do you mean by furnishings? An airator isn't needed. Most HOB filters will make enough surface agitation to create good air exchange. Any plants will also help. Plants will also help create hiding spots for fry.
Mrsoftey2
12-17-2003, 6:53 PM
plants and decorations!
Java fern, java moss, hornwort and water sprite all work in brackish water. As for decorations, any will work. Rocks are nice (any type will do) or else what ever fancy ceramic decoration you like will do.
Pufferpunk
12-17-2003, 8:47 PM
Keep in mind, most of those plants won't make it past 1.005. How big is your tank? What BW fish do you want?
Mrsoftey2
12-17-2003, 9:15 PM
i might keep my tank fw my tank is 20 gallon long i thinking about guppies mollies and swordtail. right now i have 2 zebra danios and an albaino cory in my tank
I'll add the caution note that shifting an operating tank from FW to BW should not be increased by much more than 0.002 per week. At some point, the bacteria shift to different species, and that change-over is poorly defined to date. If done slowly, you are unlikely to ever see detectable ammonia or nitrites.
jtdecoff
01-15-2004, 2:30 AM
I turned my tank into a brackish tank about 40 days ago. It has been going great and i had turned it from a fresh water tank to a brackish tank. there are some fish that are living in there that shouldn't be i have a blue tetra , and TWO GREEN CORY's that are totally living fine and show no signs of dying anytime soon. and my tank is at 5 tbs/ gallon of salt, and it is a 55 gallon tank. So it is possible that if you acclimate slowly to the brackish that some of the fish will survive, it all depends on each individual fish and how it copes with the changing situation. You would be able to live in a smog filled city wouldn't you?
It seems rather silly to take the chance that "some fish will survive" if you go slowly enough. Why try to keep fish that aren't brackish in brackkish conditions. If it doesn''t help them live longer better lives then it seems silly to do. Keep 2 tanks if you like brackish and freshwater species. Cory cats can live for 5 or more years if properly cared for but I doubt they will in a highly brackish setup.
cdawson
01-15-2004, 10:22 AM
Originally posted by jtdecoff
I turned my tank into a brackish tank about 40 days ago. It has been going great and i had turned it from a fresh water tank to a brackish tank. there are some fish that are living in there that shouldn't be i have a blue tetra , and TWO GREEN CORY's that are totally living fine and show no signs of dying anytime soon. and my tank is at 5 tbs/ gallon of salt, and it is a 55 gallon tank. So it is possible that if you acclimate slowly to the brackish that some of the fish will survive, it all depends on each individual fish and how it copes with the changing situation. You would be able to live in a smog filled city wouldn't you?
Depending on whether you're using the right type of salt, cories could tolerate aquarium salt. However there is no way for even short periods of time they'd be able to tolerate marine salt. The salt burns the skin of fish whom aren't able to tolerate the salt and slowly kills them over time. Do YOU want to do that to your cories?